Give jail(8) the feature to allow raw sockets from within a

jail, which is less restrictive but allows for more flexible
jail usage (for those who are willing to make the sacrifice).
The default is off, but allowing raw sockets within jails can
now be accomplished by tuning security.jail.allow_raw_sockets
to 1.

Turning this on will allow you to use things like ping(8)
or traceroute(8) from within a jail.

The patch being committed is not identical to the patch
in the PR.  The committed version is more friendly to
APIs which pjd is working on, so it should integrate
into his work quite nicely.  This change has also been
presented and addressed on the freebsd-hackers mailing
list.

Submitted by: Christian S.J. Peron <maneo@bsdpro.com>
PR: kern/65800

1 files changed, 13 insertions, 2 deletions

diff --git a/sys/net/rtsock.c b/sys/net/rtsock.c
index 9dc8202..7094bf7 100644
--- a/sys/net/rtsock.c
+++ b/sys/net/rtsock.c
@@ -48,6 +48,8 @@
 #include <net/raw_cb.h>
 #include <net/route.h>
 
+#include <netinet/in.h>
+
 MALLOC_DEFINE(M_RTABLE, "routetbl", "routing tables");
 
 /* NB: these are not modified */
@@ -287,6 +289,7 @@ route_output(struct mbuf *m, struct socket *so)
 	int len, error = 0;
 	struct ifnet *ifp = NULL;
 	struct ifaddr *ifa = NULL;
+	struct sockaddr_in jail;
 
 #define senderr(e) { error = e; goto flush;}
 	if (m == NULL || ((m->m_len < sizeof(long)) &&
@@ -400,8 +403,16 @@ route_output(struct mbuf *m, struct socket *so)
 				if (ifp) {
 					info.rti_info[RTAX_IFP] =
 					    ifaddr_byindex(ifp->if_index)->ifa_addr;
-					info.rti_info[RTAX_IFA] =
-						rt->rt_ifa->ifa_addr;
+					if (jailed(so->so_cred)) {
+						jail.sin_family = PF_INET;
+						jail.sin_len = sizeof(jail);
+						jail.sin_addr.s_addr =
+						htonl(prison_getip(so->so_cred));
+						info.rti_info[RTAX_IFA] =
+						(struct sockaddr *)&jail;
+					} else
+						info.rti_info[RTAX_IFA] =
+							rt->rt_ifa->ifa_addr;
 					if (ifp->if_flags & IFF_POINTOPOINT)
 						 info.rti_info[RTAX_BRD] =
 							rt->rt_ifa->ifa_dstaddr;